setns: setup directory at kernel/syscalls/setns

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
setns: add new syscall test setns01

errno tests for setns(2) - reassociate thread with a namespace

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
setns: add new syscall test setns02

functional test for setns(2) - reassociate thread with a namespace
involving CLONE_NEWIPC and CLONE_NEWUTS.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
kill/1-2.c: fix potential bug

If fork() fails,this case will cause unexpected problem when kill(-1,...) called by root.

Signed-off-by: DAN LI <li.dan@cn.fujitsu.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>